- Biopsy A piece of tissue or tumor is removed for examination under the microscope. When a biopsy is done in the neck area, a small amount of anesthetic is injected into the area of the biopsy. The biopsy may be done with 1) a small needle to pull out some tissue, 2) a cookie-cutter-like instrument to punch out a small piece of tissue, or 3) a small knife to cut out a piece of tissue. A knife biopsy may be done in the operating room or the clinic depending on the location of the biopsy and precautions required.